A small proton charge radius from an electron-proton scattering experiment.

Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, rp. In 2010, a new method using muonic hydrogen atoms1 found a substantial discrepancy compared with previous results2, which became known as the 'proton radius puzzle'. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen3,4. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e-p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e-p experiments and enabled measurements at very small forward-scattering angles. Our result, rp = 0.831 ± 0.007stat ± 0.012syst femtometres, is smaller than the most recent high-precision e-p measurement5 and 2.7 standard deviations smaller than the average of all e-p experimental results6. The smaller rp we have now measured supports the value found by two previous muonic hydrogen experiments1,7. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant8-one of the most accurately evaluated fundamental constants in physics.

Measurements of Nonsinglet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for Q

We present extractions of the nucleon nonsinglet moments utilizing new precision data on the deuteron F_{2} structure function at large Bjorken-x determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world datasets on the proton and deuteron at lower x measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the x range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high x data. Moreover, recent exciting developments in lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach that first calculates the quark distributions directly before determining moments.

[Recurrent postpartum pyoderma gangrenosum and fatal cardiomyopathy]. / Pyoderma gangrenosum récidivant du post-partum et cardiomyopathie fatale.

BACKGROUND: We report a case of recurrent post-partum pyoderma gangrenosum (PG) complicated by post-partum cardiomyopathy (PPCM). PATIENTS AND METHODS: A 23-year-old woman presented with a previous medical history of aseptic abscess of the left breast in her fourth pregnancy, which developed after surgical drainage of an inflammatory ulceration treated by atraumatic topical care. During her fifth pregnancy, the patient presented a large and painful ulceration in relation to the scar of the Caesarean section, despite the introduction of broad-spectrum antibiotic therapy. Bacteriological samples were negative. Histological examination militated in favor of PG. One week after initiation of corticosteroid therapy, the patient suddenly showed signs of heart failure. Based on trans-thoracic echocardiography PPCM was diagnosed, and the outcome was fatal. DISCUSSION: This observation raises the question of the relationship between PG and pregnancy and describes the association of PG and PPCM. PG occurs rarely during pregnancy and it may be induced by the rise in G-CSF levels found in pregnant women. The association with PPCM seen in our patient could have been due to the development of an anti-angiogenic climate at the end of pregnancy, together with inflammatory myocardial aggression linked to the PG.

[Frontal fibrosing alopecia: A prospective study of 20 cases]. / Alopécie frontale fibrosante : étude prospective de 20 cas.

BACKGROUND: Frontal fibrosing alopecia (FFA) is a variant of lichen planopilaris predominantly affecting postmenopausal women. We report a series of 20 cases of FFA and describe the epidemiological, clinical, dermoscopic features and progress under treatment. PATIENTS AND METHODS: This was a prospective study conducted over a period of 16 months in patients seen at the dermatology department of the Hassan II University in Fez, Morocco. RESULTS: Mean patient age was 46 years. Patients were premenopausal in 65% of cases. Dermoscopic examination revealed specific signs of the disease. Skin biopsy guided by dermoscopy confirmed the diagnosis of lichen planus pilaris in its FFA variant in all cases. Immune dysfunctions and other disorders were noted in half of the cases. Various treatments had been initiated, including topical corticosteroids, tacrolimus ointment, minoxidil 2%, hydroxychloroquine, and oral finasteride. The results were satisfactory with a decline within one year. CONCLUSION: FFA is increasingly widely described in premenopausal women. Dermoscopy may be used to facilitate diagnosis, guide biopsy, evaluate treatment efficacy and establish a prognosis.

Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton.

Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θ_{cm}^{p}=70°. The longitudinal transfer K_{LL}, measured to be 0.645±0.059±0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude.

[Sporadic anterior cervical hypertrichosis]. / Hypertrichose cervicale antérieure sporadique.

BACKGROUND: Anterior cervical hypertrichosis is a rare and little-known form of congenital localized hypertrichosis. It is characterized by the presence of a tuft of terminal hairs in the anterior cervical region. We report four typical clinical observations of this condition. PATIENTS AND METHODS: Four patients aged from 5 to 21 years were seen for a tuft of terminal long hair on the neck, next to the cricoid cartilage, recorded at birth or during early childhood. There was no indication of previous trauma or topical drug application. No similar familial history was found. In one case, histological examination performed for suspicion of an "atypical" smooth muscle hamartoma contributed nothing of note. No neurological abnormalities were observed. In one case there was a history of chronic juvenile idiopathic arthritis and familial thyroid disease. Treatment with 5 sessions of laser hair removal was proposed in one case and the improvement was considered satisfactory by the patient. DISCUSSION: Anterior cervical hypertrichosis constitute a specific clinical picture of a benign nature, and is sometimes associated with neurological, orthopaedic or ocular abnormalities. Although rarely reported, its frequency is probably underestimated.

[Eosinophilic fasciitis, morphea and vitiligo in a single patient]. / Association fasciite avec éosinophilie, morphées et vitiligo.

BACKGROUND: Fasciitis with eosinophilia (FE), or Shulman syndrome, is a rare disease of unknown origin for which the nosological profile has not been clearly defined. It is clinically characterised by oedema and induration of the limbs with hypereosinophilia. It may be associated with morphea, in which case it carries a poor prognosis, or other diseases, particularly autoimmune conditions. Herein, we report a case of fasciitis associated with eosinophilia, morphea and vitiligo. PATIENT AND METHODS: A 45-year-old male patient followed up for vitiligo for 20 years had been presenting swelling and induration of the skin on all 4 limbs for the previous 7 months associated with morphea on the trunk. Treatment consisting of systemic corticosteroids and methotrexate was initiated and displayed a certain degree of efficacy. DISCUSSION: The association of morphea/fasciitis with eosinophilia is a classical finding; the presence of vitiligo raises the question of possible association between these different disorders.

Polarization components in π0 photoproduction at photon energies up to 5.6 GeV.

We present new data for the polarization observables of the final state proton in the (1)H(γ,p)π(0) reaction. These data can be used to test predictions based on hadron helicity conservation and perturbative QCD. These data have both small statistical and systematic uncertainties and were obtained with beam energies between 1.8 and 5.6 GeV and for π(0) scattering angles larger than 75° in the center-of-mass frame. The data extend the polarization measurements database for neutral pion photoproduction up to E(γ)=5.6 GeV. The results show a nonzero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and π(0) scattering angle in the center-of-mass frame. This indicates that hadron helicity conservation does not hold and that the perturbative QCD limit is still not reached in the energy regime of this experiment.

Syndrome De Lyell Et Syndrome De Stevens-Johnson: Étude Rétrospective De 30 Cas.

Stevens-Johnson syndrome and Lyell syndrome are severe bullous drug reactions that can be life-threatening. The aim of this study is to describe the epidemiological, etiological, clinical, therapeutic and evolutionary data of patients hospitalized in our Dermatology Department. This is a retrospective descriptive study over a period of 10 years. All records of patients admitted to the Dermatology Department for these cutaneous adverse drug reactions were included. A total of 30 patients were recorded, with a male predominance. There were 18 cases of Lyell syndrome, 8 cases of Stevens-Johnson syndrome and 4 cases of overlap syndrome. The mean time to onset after drug administration was 7.5 days. The average skin area detached was 48%. Visceral involvement was frequently observed: pulmonary involvement, renal involvement, hepatic cytolysis and hematological involvement. The notion of medication was found in all our patients, with self-medication in 23% of cases. The reason for prescription was dominated by post-surgical anticonvulsant prophylaxis. All our patients received symptomatic treatment, and corticosteroid therapy was administered in only one patient for macrophagic activation syndrome. The mortality rate was of 17%. Skin area involved, presence of renal failure or respiratory distress were the main prognostic factors.

An open-label trial of rituximab therapy in pulmonary alveolar proteinosis.

Rituximab, a monoclonal antibody directed against the B-lymphocyte antigen CD20, has shown promise in several autoimmune disorders. Pulmonary alveolar proteinosis (PAP) is an autoimmune disorder characterised by autoantibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF). An open-label, proof-of-concept phase II clinical trial was conducted in 10 PAP patients. The intervention consisted of two intravenous infusions of rituximab (1,000 mg) 15 days apart. Bronchoalveolar lavage (BAL) fluid and peripheral blood samples were collected. The primary outcome was improvement in arterial blood oxygenation. Both arterial oxygen tension and alveolar-arterial oxygen tension difference in room air improved in seven out of the nine patients completing the study. Lung function and high-resolution computed tomography scans, which were secondary outcomes, also improved. Peripheral blood CD19+ B-lymphocytes decreased from mean ± sem 15 ± 2% to <0.05% (n = 10) 15 days post-therapy. This decrease persisted for 3 months in all patients; at 6 months, CD19+ B-cells were detected in four out of seven patients (5 ± 2%). Total anti-GM-CSF immunoglobulin (Ig)G levels from baseline to 6 months were decreased in BAL fluids (n = 8) but unchanged in sera (n = 9). In this PAP cohort: 1) rituximab was well-tolerated and effectively ameliorated lung disease; and 2) reduction in anti-GM-CSF IgG levels in the lung correlated with disease changes, suggesting that disease pathogenesis is related to autoantibody levels in the target organ.